Direct catalytic conversion of alcohols to olefins of higher carbon number with reduced ethylene production

ABSTRACT

A catalyst composition for converting an alcohol to olefins, the catalyst composition comprising the following components: (a) a support (e.g., particles) comprising silicon and oxygen; (b) at least one of copper and silver residing on and/or incorporated into said support; and (c) at least one lanthanide element residing on and/or incorporated into said support. The catalyst may also further include component (d), which is zinc. Also described herein is a method for converting an alcohol to one or more olefinic compounds (an olefin fraction) by contacting the alcohol with a catalyst at a temperature of at least 100° C. and up to 500° C. to result in direct conversion of the alcohol to an olefin fraction containing one or more olefinic compounds containing at least three carbon atoms; wherein ethylene and propylene are produced in a minor proportion of the olefin fraction, and butenes and higher olefins are produced in major proportion.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. patent applicationSer. No. 17/584,651 filed on Jan. 26, 2022, which claims benefit of U.S.Provisional Application No. 63/141,996 filed on Jan. 27, 2021, all ofthe contents of which are incorporated herein by reference.

GOVERNMENT SUPPORT

This invention was made with government support under Prime Contract No.DE-AC05-000R22725 awarded by the U.S. Department of Energy. Thegovernment has certain rights in the invention.

FIELD OF THE INVENTION

The present invention relates, generally, to the catalytic conversion ofalcohols to hydrocarbons, and more particularly, to zeolite-basedcatalytic methods for conversion of alcohols, such as ethanol, toolefins.

BACKGROUND OF THE INVENTION

As part of a continuing effort in finding more cost-effective,environmentally friendly, and independent solutions to fuel productionand consumption, the conversion of ethanol and other alcohols tohydrocarbons has become an active field of study. Ethanol, inparticular, is of particular interest as an alcohol feedstock because ithas the potential to be made in large quantity by renewable means (e.g.,fermentation of biomass or syngas fermentation). However, severalhurdles need to be overcome before such a process can becomeindustrially feasible for producing olefins and hydrocarbon blendstocksof substantial equivalence to jet fuel, gasoline and other petrochemicalfuels.

A few ethanol conversion technologies for jet fuel production arecurrently available. One approach is via ethanol dehydration to ethylenefollowed by two-step oligomerization to jet-range and gasoline-rangehydrocarbons, and hydrogenation. This technology requires significantenergy input due to the endothermic dehydration reaction. The ethyleneoligomerization step is generally costly. Moreover, two steps are neededto convert ethanol to butene-rich olefins. The overall conversioninvolves four key steps: ethanol dehydration, ethylene dimerization,butene-rich olefin oligomerization, and hydrotreating. In addition,selective production of butene-rich olefins from ethylene overheterogeneous catalysts remains challenging due to substantial formationof side products (e.g., aromatics and light paraffins). To mitigateformation of such side products, the process is often operated at mediumconversion of ethylene, which leads to an additional step ofenergy-intensive ethylene separation from light C₃-C₄ olefins. Lastly,this technology lacks the opportunity for generating a significantamount of diesel fuel and other high-value chemicals, which has highervalue than either gasoline or jet fuel, and the demand of renewablediesel is also rapidly increasing. Another approach is to convertethanol to isobutylene via a mixed oxide catalyst, followed byoligomerization and hydrogenation. A major limitation in the foregoingprocess is the low carbon efficiency due to a significant amount ofcarbon dioxide formation.

Acetone-butanol-ethanol (ABE) fermentation, a well-known commercialprocess, has recently regained significant interest for on-purposen-butanol production. The ABE fermentation products are known to beimportant building blocks for middle distillate fuel (jet or dieselfuels) production. Direct dehydration of butanol is usually employed toproduce butenes, which are then oligomerized to liquid hydrocarbon fuelscontaining primarily gasoline and jet-range hydrocarbons, and minordiesel range hydrocarbons due to low carbon number of butenes. The otherfermentation products (e.g., ethanol) can be converted to ethylene,which is more challenging to convert to middle distillate fuels.

Another process for converting ABE to fuels is via cascadedehydrogenation, aldol condensation, alkylation reactions, followed byhydrogenation and hydrotreating reactions (Nature, 2012, 491, 235).Water poisoning and deactivating aldol condensation catalysts are wellknown, and water has been shown to inhibit the reported ABE to fuelsreactions. Water separation from ABE fermentation products requires anenergy-intensive separation process. The energy cost associated with ABEseparation is substantial (˜14%) for biological ABE production. Thus,there remains an as yet unrealized need to develop an ABE conversiontechnology that can mitigate the need for water removal and productseparations. Similar challenges remain for other butanol to middledistillate conversion process. A few other challenges related to thistechnology include limited product yield and reliance on a high loadingof precious metals (e.g., 5% Pd/C).

In view of the numerous disadvantages associated with currently knownconversion processes, there would be a significant benefit in a processthat could produce olefins (and ultimately, a synthetic fossil fuel)from alcohols with a higher carbon efficiency and at the same or lowercost than known in the art. There would be a particular advantage insuch a process that could mitigate or avoid the costly endothermicethanol dehydration step, the energy-intensive ethylene separation step,the overall number of steps, and the production of paraffins andaromatics.

SUMMARY OF THE INVENTION

The present disclosure is directed to catalysts useful in the conversionof alcohols to olefins, as well as methods for the conversion ofalcohols to olefins by use of these catalysts. The catalysts describedherein can produce olefins from alcohols with high carbon efficiency andat the same or lower cost than conventional methods. The presentdisclosure describes a more efficient and direct technology forconverting ethanol to hydrocarbon fuels, particularly middle distillatehydrocarbon fuels. The process provides the following additionalbenefits: 1) avoids the additional endothermic ethanol dehydration step;2) mitigates or avoids an energy-intensive ethylene separation step bysignificantly reducing ethylene production; 3) can reduce the number ofkey ethanol conversion steps from four or five to three, offering agreat opportunity to reduce capital and operating expenses; and 4) canreduce or substantially eliminate formation of paraffins and aromaticsduring ethanol conversion, which offers the potential to increase themiddle distillate yield.

The catalyst composition includes precisely or at least the followingcomponents: (a) a support (typically made of particles) containing atleast silicon and oxygen atoms; (b) at least one of copper and silveratoms residing on and/or incorporated into the support; and (c) at leastone lanthanide element (e.g., La, Ce, or higher atomic numberlanthanide) residing on and/or incorporated into the support. Inseparate or further embodiments, the catalyst may further include zinc(Zn) residing on and/or incorporated into the support particles,integrated into or with component (b), or component (c), or integratedinto or with both components (b) and (c). In some embodiments, allsupport particles have the same composition. In the foregoing scenario,a portion of the support particles may contain (i.e., residing thereonand/or incorporated therein) component (b) and not component (c), and aportion of the support particles may contain component (c) and notcomponent (b), or alternatively, all support particles may containcomponent (b) and component (c). In other embodiments, the supportparticles include at least a first set of support particles and a secondset of support particles having different compositions. In the foregoingscenario, the first set of support particles may contain component (b)and not component (c), and the second set of support particles maycontain component (c) and not component (b), or alternatively, at leastthe first set of support particles and the second set of supportparticles contain component (b) and component (c). In separate orfurther embodiments, at least a portion of the support particles have asilica composition. In separate or further embodiments, at least aportion of the support particles include aluminum atoms and have azeolite composition, wherein the zeolite composition may be partiallydealuminated and have a silicon to aluminum ratio of at least or above 5or 10, or the dealuminated zeolite composition may not contain aluminum(i.e., be completely dealuminated and composed of only silicon oxide andoptionally one or more other elements in a trace amount). In separate orfurther embodiments, component (b) or component (c) is present by weightof support particles in an amount of 0.5-20 wt % or 0.5-30 wt %.

In the conversion method, the alcohol is contacted with any of theabove-described catalyst compositions at a temperature of at least 100°C. and up to 500° C. to result in direct conversion of the alcohol to anolefin fraction comprising one or more olefinic compounds containing atleast three or more carbon atoms. The method may also produce ethylenein an amount of no more than or less than 5 vol % in the olefinfraction. The method may alternatively or in addition produce propene inan amount of no more than or less than 25 vol % in the olefin fraction.The method may alternatively or in addition produce butenes in an amountof least or above 20, 25, or 30 vol % in the olefin fraction. Inseparate or further embodiments, alkanes (e.g., paraffins) areoptionally produced along with the olefin fraction in an amount of nomore than or less than 2 or 3 vol %. In separate or further embodiments,aromatics are optionally produced along with the olefin fraction in anamount of no more than or less than 1 or 2 vol %. In separate or furtherembodiments, olefins containing at least five carbon atoms are presentin the olefin fraction in an amount of at least or above 20, 30, or 40vol %. In separate or further embodiments, the alcohol has one to fourcarbon atoms, or the alcohol more specifically is or includes ethanol.In separate or further embodiments, the alcohol is in aqueous solutionin a concentration of no more than 60, 50, 40, 30, or 20 vol %. Inseparate or further embodiments, the alcohol is a component of afermentation stream, or more particularly, an acetone-butanol-ethanol(ABE) fermentation stream, 2,3-butanediol fermentation stream, or1-butanol/isobutanol fermentation stream, when contacted with thecatalyst.

In the process, ethanol is converted to higher olefins, e.g., butenesand hexenes, which can be readily converted to jet fuel or othersynthetic fossil fuel with high carbon efficiency and lowoligomerization cost. Moreover, the reactions proceed with negligibleCO₂ formation. At the same time, the process is also amenable forproducing 1,3-butadiene, which is a high value commodity chemical sinceit is used as a precursor for a number of applications, including in theproduction of rubber and plastics.

The new catalyst materials have the ability to convert either purealcohols or aqueous solutions thereof into jet fuel and valuableco-products (e.g., 1,3-butadiene). In particular embodiments, thepresent disclosure is directed to a method for converting ethanol toliquid hydrocarbon fuels via 1) one-step ethanol conversion to C₃₊olefins with significant production of C₅₊ olefins, 2) oligomerization,and 3) hydrotreating. In the first step, ethanol is converted to C₃₊olefins in one step without an ethanol dehydration step. This step maybe achieved over a copper-modified Lewis acid catalyst, such as aCu-modified La-based Beta zeolite (e.g., Cu—Zn—La/Beta orCu/SiO₂-Zn/La/Beta). The present disclosure particularly demonstratesthat ethanol can be converted to C₃₊ olefins over three La-basedcatalysts, including Cu—Zn—La/Beta catalyst, Cu/SiO₂-Zn/La/Betacatalyst, and Cu/SiO₂-La/Beta at about 350° C. and ambient pressureunder a hydrogen environment. Ethanol conversion of greater than 97% canbe achieved with greater than 80% C₃₊ olefins selectivity. The C₅₊olefins selectivity may be as high as 62% or higher. For the secondstep, the C₃₊ olefins may be readily oligomerized to diesel-range ormiddle-distillate-range hydrocarbons over solid acid catalysts (e.g.,zeolites) along with production of gasoline-range and jet-rangehydrocarbons, or more particularly, production of jet and diesel fuels.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1B. FIG. 1A is a schematic of an exemplary process forconverting ethanol or other alcohol to C₄₊ olefins, or co-producing1,3-butadiene, optionally followed by oligomerization and hydrogenationto form gasoline, diesel and jet fractions. FIG. 1B is a schematic of anexemplary process for converting butanol (such as from an ABE process)or other alcohol to C₄₊ olefins, optionally followed by oligomerizationand hydrogenation to form gasoline, diesel and jet fractions.

FIG. 2 . Graph showing ethanol conversion and product selectivities overCu-7Ce/Beta catalyst and Cu-11.6Ce/Beta catalyst at 623 K, 101.3 kPa,WHSV=0.52 h⁻¹, 7.1 kPa ethanol balanced with H₂.

FIG. 3 . Graph showing ethanol conversion and product selectivities overfour Cu—Ce/Beta catalysts at 623 K, 101.3 kPa, WHSV=0.52 h⁻¹, 7.1 kPaethanol balanced with H₂.

FIG. 4 . Graph showing ethanol conversion and product selectivities overCu—La/Beta catalyst at 623 K, 101.3 kPa, WHSV=0.52 h⁻¹, 7.1 kPa ethanolbalanced with He.

FIG. 5 . Graph showing theoretical and actual selectivities achieved byconversion of ABE fermentation stream over Cu—Zn—La/Beta catalyst at 623K, WHSV=0.54 h⁻¹, 2.70 kPa 1-butanol, 1.73 kPa acetone, and 0.728 kPaethanol balanced with 96.1 kPa H₂.

FIG. 6 . Graph showing selectivities for conversion of 1-butanol, andtheoretical and actual product selectivities achieved by conversion of amixture of 1-butanol and ethanol over Cu/silica+Zn-La/Beta. For1-butanol feed, the reaction was carried out at 623 K, WHSV=0.54 h⁻¹,4.59 kPa 1-butanol and 96.7 kPa H₂. For the mixture feed, the reactionwas performed at 623 K, 101.3 kPa, WHSV=0.44 h⁻¹, 2.29 kPa 1-butanol and2.30 kPa ethanol balanced with 96.7 kPa H₂.

DETAILED DESCRIPTION OF THE INVENTION

In a first aspect, the present disclosure is directed to a catalystcomposition useful for converting an alcohol to olefin compounds (i.e.,olefin fraction). The catalyst composition includes or exclusivelycontains the following components: (a) support particles composed of atleast silicon and oxygen atoms, (b) at least one of copper (Cu) andsilver (Ag) atoms residing on and/or incorporated into the supportparticles, and (c) at least one lanthanide element residing on and/orincorporated into the support particles. In some embodiments, thecatalyst further includes: (d) zinc atoms residing on and/orincorporated into the support particles, integrated into eithercomponent (a), or component (b), or integrated into both components (a)and (b).

In one set of embodiments, the support particles are silica particles,i.e., the support particles are composed of only silicon and oxygenatoms. The silica support particle may or may not contain a trace amountof one or more other elements (e.g., Al, Mg, Ca, K, Na, Fe, B, P, Zn,Cu, Ni, and/or Cd), typically in a total amount of no more than or lessthan 0.5, 0.2, 0.1, 0.01, 0.001, or 0.0001 wt %, depending on thepurity.

In another set of embodiments, at least a portion or all of the supportparticles further include aluminum atoms and have a zeolite compositionhaving any of the silicon to aluminum ratios disclosed earlier above oras set forth below. In other embodiments, at least a portion or all ofthe support particles have a zeolite composition after completedealumination, i.e., with no aluminum present. The zeolite can be any ofthe porous aluminosilicate structures known in the art that are stableunder high temperature conditions, i.e., of at least 100° C., 150° C.,200° C., 250° C., 300° C., and higher temperatures up to, for example,500° C., 550° C., 600° C., 650° C., 700° C., 750° C., 800° C., 850° C.,or 900° C. In particular embodiments, the zeolite is stable from atleast 100° C. and up to 700° C. Typically, the zeolite is ordered byhaving a crystalline or partly crystalline structure. The zeolite cangenerally be described as a three-dimensional framework containingsilicate (SiO₂ or SiO₄) and aluminate (Al₂O₃ or AlO₄) units that areinterconnected (i.e., crosslinked) by the sharing of oxygen atoms.

In various embodiments, the zeolite (whether aluminated, partiallydealuminated, or completely dealuminated) is a MFI-type zeolite,MWW-type zeolite, MEL-type zeolite, MTW-type zeolite, MCM-type zeolite,BEA-type zeolite, kaolin, or a faujasite-type of zeolite. Someparticular examples of zeolites include the pentasil zeolites, and moreparticularly, the ZSM class of zeolites (e.g., ZSM-5, ZSM-8, ZSM-11,ZSM-12, ZSM-15, ZSM-23, ZSM-35, ZSM-38, ZSM-48), zeolite X, zeolite Y,zeolite beta (i.e., Beta zeolite or BEA), and the MCM class of zeolites(e.g., MCM-22 and MCM-49). The compositions, structures, and propertiesof these zeolites are well-known in the art, and have been described indetail, as found in, for example, U.S. Pat. Nos. 4,721,609, 4,596,704,3,702,886, 7,459,413, and 4,427,789, the contents of which areincorporated herein by reference in their entirety. The zeolite can alsohave any suitable silica-to-alumina (i.e., SiO₂/Al₂O₃ or “Si/Al”) ratio.For example, the zeolite can have a Si/Al ratio of precisely, at least,more than, less than, or up to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,13, 14, 15, 20, 25, 30, 35, 40, 45, 55, 60, 65, 70, 75, 80, 85, 90, 95,100, 120, 150, 200, 300, 400, or 500, or a Si/Al ratio within a rangebounded by any two of the foregoing values. As aluminum is present inany of the foregoing zeolite compositions having any of the recitedSi/Al ratios, any such zeolite is herein considered to be partiallydealuminated. The zeolite may also be completely dealuminated, in whichcase the zeolite does not contain aluminum, and thus, cannot have aSi/Al ratio. In some embodiments, the zeolite is at least partiallydealuminated and has a Si/Al ratio of at least or above 5, 10, 15, 20,25, or 30, including any of the Si/Al ratios over delineated above. Insome embodiments, the zeolite is a 2D pillared zeolite, as well known inthe art. The 2D pillared zeolite can be a 2D pillared version of any ofthe zeolites described above, such as a pillared MFI or MWW zeolite.

In particular embodiments, the zeolite (whether aluminated, partiallydealuminated, or completely dealuminated) is a Beta (BEA) zeolite. TheBEA zeolite may possess any suitable Si/Al ratio, including any of theratios provided above. For example, the BEA zeolite can have a Si/Alratio of precisely, at least, more than, less than, or up to 1, 2, 3, 4,5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 55,60, 65, 70, 75, 80, 85, 90, 95, 100, 120, 150, 200, 250, 300, 350, 400,450, or 500, or a Si/Al ratio within a range bounded by any two of theforegoing values. As aluminum is present in any of the foregoing Betazeolite compositions having any of the recited Si/Al ratios, any suchzeolite is herein considered to be partially dealuminated. The Betazeolite may also be completely dealuminated, in which case the Betazeolite does not contain aluminum, and thus, cannot have a Si/Al ratio.Beta zeolite compositions having a Si/Al ratio of at least or greaterthan 100, 200, or 500 are particularly considered herein as dealuminatedBeta zeolites. Notably, in some embodiments, a pure silica (no Al) Betazeolite-type framework may be used. In some embodiments, the pure silicazeolite-type framework may also be a pillared zeolite.

In some embodiments, all support particles in the catalyst have the samecomposition, e.g., all silica, or all a particular zeolite, such as aBeta zeolite or ZSM (e.g., ZSM-5) zeolite. In other embodiments, atleast two different types of support particles are present, e.g., silicaadmixed with zeolite (e.g., beta or ZSM zeolite) support particles, orat least two different types of zeolite support particles selected fromany of the zeolite compositions provided earlier above, e.g., Betazeolite admixed with a ZSM (e.g., ZSM-5) zeolite.

Any of the various types of support particles described above may haveany of the particle sizes well known in the art. In differentembodiments, the support particles have a size of precisely or about,for example, 0.1, 0.2, 0.5, 1, 2, 3, 4, 5, or 10 microns, or a particlesize within a range bounded by any two of the foregoing values. In someembodiments, the particle size is substantially uniform, such asreflected in a deviation of no more than ±1, 2, or 10% from a particularsize selected from the above exemplary values. In other embodiments, theparticle size is substantially broad, such as reflected in a deviationof about or at least ±20, 30, 40, 50, or more from a particular sizeselected from the above exemplary values. The substantially broadparticle size may also be characterized by monomodal, bimodal, trimodal,or higher modal distribution.

At least a portion of any of the types of support particles describedabove, including any of the silica or zeolite types of supportsdescribed above, contains component (b), wherein component (b) includesor exclusively contains at least one of copper (Cu) and silver (Ag)residing on and/or incorporated into the support particles. The Cuand/or Ag atoms are present in their ionic (non-metallic) state incomponent (b). In some embodiments, at least a portion or all of thesupport particles contain Cu atoms, with Ag atoms absent or present. Inother embodiments, at least a portion or all of the support particlescontain Ag atoms, with Cu atoms absent or present. In other embodiments,both Cu and Ag atoms are present in at least a portion or all of thesupport particles. In particular embodiments, the Cu and/or Ag atoms arepresent in silica support particles, and the silica support particlesmay or may not be in admixture with any of the zeolite support particlesdescribed above. In other particular embodiments, the Cu and/or Ag atomsare present in zeolite support particles, or more particularly, Betazeolite support particles, and the zeolite support particles may or maynot be in admixture with any of the silica support particles describedabove. Component (b) is typically present by weight of support particlesin an amount of 0.5-20 wt %. In different embodiments, component (b) ispresent in an amount of precisely or about 0.5, 1, 2, 3, 4, 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 wt %, or an amountwithin a range bounded by any two of the foregoing values (e.g., 0.5-20wt %, 0.5-15 wt %, 0.5-10 wt %, 1-20 wt %, 1-15 wt %, or 1-10 wt %).

At least a portion of any of the types of support particles describedabove, including any of the silica or zeolite types of supportsdescribed above, also contains component (c), wherein component (c)includes or exclusively contains at least one type of lanthanide elementresiding on and/or incorporated into the support particles. Thelanthanide elements are present in their ionic (non-metallic) state incomponent (c). The term “lanthanide element” refers to any of theelements having an atomic number of 57-71, e.g., lanthanum (La), cerium(Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm),europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium(Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu). Inparticular embodiments, component (c) is or includes lanthanum and/orcerium. In particular embodiments, the lanthanide atoms are present insilica support particles, and the silica support particles may or maynot be in admixture with any of the zeolite support particles describedabove. In other particular embodiments, the lanthanide atoms are presentin zeolite support particles, or more particularly, Beta zeolite supportparticles, and the zeolite support particles may or may not be inadmixture with any of the silica support particles described above.Component (c) is typically present by weight of support particles in anamount of 0.5-30 wt %. In different embodiments, component (c) ispresent in an amount of precisely or about 0.5, 1, 2, 3, 4, 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26,27, 28, 29, or 30 wt %, or an amount within a range bounded by any twoof the foregoing values (e.g., 0.5-30 wt %, 0.5-25 wt %, 0.5-20 wt %,0.5-15 wt %, 0.5-10 wt %, 1-30 wt %, 1-25 wt %, 1-20 wt %, 1-15 wt %, or1-10 wt %).

In some embodiments, the catalyst further includes zinc (Zn) atoms, intheir ionic state, residing on and/or incorporated into at least aportion of the support particles. In a first embodiment, the Zn ions areincluded in support particles also containing component (b). In a secondembodiment, the Zn ions are included in support particles alsocontaining component (c). In a third embodiment, the Zn ions areincluded in support particles also containing components (b) and (c).

In a first set of embodiments, all support particles have the samecomposition and all support particles contain component (b) andcomponent (c). An example of such a catalyst is one in which all supportparticles have a silica composition and all silica support particlescontain copper and lanthanum, or copper, lanthanum, and zinc. Anotherexample of such a catalyst is one in which all support particles have azeolite (e.g., Beta zeolite or ZSM-5 zeolite, typically partially orcompletely dealuminated) composition and all zeolite support particlescontain copper and lanthanum, or copper, lanthanum, and zinc. Anotherexample of such a catalyst is one in which all support particles have asilica composition and all silica support particles contain silver andlanthanum, or silver, lanthanum, and zinc. Another example of such acatalyst is one in which all support particles have a zeolite (e.g.,Beta zeolite or ZSM-5 zeolite, typically partially or completelydealuminated) composition and all zeolite support particles containsilver and lanthanum, or silver, lanthanum, and zinc. Another example ofsuch a catalyst is one in which all support particles have a silicacomposition and all silica support particles contain copper and cerium,or copper, cerium, and zinc. Another example of such a catalyst is onein which all support particles have a zeolite (e.g., Beta zeolite orZSM-5 zeolite, typically partially or completely dealuminated)composition and all zeolite support particles contain copper and cerium,or copper, cerium, and zinc. Another example of such a catalyst is onein which all support particles have a silica composition and all silicasupport particles contain silver and cerium, or silver, cerium, andzinc. Another example of such a catalyst is one in which all supportparticles have a zeolite (e.g., Beta zeolite or ZSM-5 zeolite, typicallypartially or completely dealuminated) composition and all zeolitesupport particles contain silver and cerium, or silver, cerium, andzinc.

In a second set of embodiments, all support particles have the samecomposition and a first portion of the support particles contains (i.e.,residing thereon and/or incorporated therein) component (b) and notcomponent (c), and a second portion of the support particles containscomponent (c) and not component (b). An example of such a catalyst isone in which all support particles have a silica composition, and afirst portion of the silica support particles contains only copperand/or silver, while a second portion of silica support particlescontains only lanthanum and/or cerium. Another example of such acatalyst is one in which all support particles have a zeolite (e.g.,Beta zeolite or ZSM-5 zeolite, typically partially or completelydealuminated) composition, and a first portion of the zeolite supportparticles contains only copper and/or silver, while a second portion ofzeolite support particles contains only lanthanum and/or cerium. Anotherexample of such a catalyst is one in which all support particles have asilica composition, and a first portion of the silica support particlescontains only copper and zinc, while a second portion of silica supportparticles contains only lanthanum and/or cerium. Another example of sucha catalyst is one in which all support particles have a zeolite (e.g.,Beta zeolite or ZSM-5 zeolite, typically partially or completelydealuminated) composition, and a first portion of the zeolite supportparticles contains only copper and zinc, while a second portion ofzeolite support particles contains only lanthanum and/or cerium. Anotherexample of such a catalyst is one in which all support particles have asilica composition, and a first portion of the silica support particlescontains only copper (or silver), while a second portion of silicasupport particles contains only lanthanum (or cerium) and zinc. Anotherexample of such a catalyst is one in which all support particles have azeolite (e.g., Beta zeolite or ZSM-5 zeolite, typically partially orcompletely dealuminated) composition, and a first portion of the zeolitesupport particles contains only copper (or silver), while a secondportion of zeolite support particles contains only lanthanum (or cerium)and zinc.

In a third set of embodiments, the support particles include at least afirst set of support particles and a second set of support particleshaving different compositions, and all support particles containcomponent (b) and component (c), wherein component (b) and/or (c) is thesame or different for all support particles. An example of such acatalyst is one in which the first set of support particles has a silicacomposition and the second set of support particles has a zeolite (e.g.,Beta zeolite or ZSM-5 zeolite, typically partially or completelydealuminated) composition, and the first and second sets of supportparticles contain copper and lanthanum, or copper, lanthanum, and zinc.Another example of such a catalyst is one in which the first set ofsupport particles has a partially or completely dealuminated ZSM-5zeolite composition and the second set of support particles has apartially or completely dealuminated Beta zeolite composition, and thefirst and second sets of support particles contain copper and lanthanum,or copper, lanthanum, and zinc. Another example of such a catalyst isone in which the first set of support particles has a silica compositionand the second set of support particles has a zeolite (e.g., Betazeolite or ZSM-5 zeolite, typically partially or completelydealuminated) composition, and the first and second sets of supportparticles contain copper and cerium, or copper, cerium, and zinc.Another example of such a catalyst is one in which the first set ofsupport particles has a partially or completely dealuminated ZSM-5zeolite composition and the second set of support particles has apartially or completely dealuminated Beta zeolite composition, and thefirst and second sets of support particles contain copper and cerium, orcopper, cerium, and zinc. Another example of such a catalyst is one inwhich the first set of support particles has a silica composition andthe second set of support particles has a zeolite (e.g., Beta zeolite orZSM-5 zeolite, typically partially or completely dealuminated)composition, and the first and second sets of support particles containsilver and lanthanum, or silver, lanthanum, and zinc. Another example ofsuch a catalyst is one in which the first set of support particles has apartially or completely dealuminated ZSM-5 zeolite composition and thesecond set of support particles has a partially or completelydealuminated Beta zeolite composition, and the first and second sets ofsupport particles contain silver and lanthanum, or silver, lanthanum,and zinc. Another example of such a catalyst is one in which the firstset of support particles has a silica composition and the second set ofsupport particles has a zeolite (e.g., Beta zeolite or ZSM-5 zeolite,typically partially or completely dealuminated) composition, and thefirst and second sets of support particles contain silver and cerium, orsilver, cerium, and zinc. Another example of such a catalyst is one inwhich the first set of support particles has a partially or completelydealuminated ZSM-5 zeolite composition and the second set of supportparticles has a partially or completely dealuminated Beta zeolitecomposition, and the first and second sets of support particles containsilver and cerium, or silver, cerium, and zinc.

In a fourth set of embodiments, the support particles include at least afirst set of support particles and a second set of support particleshaving different compositions, and the first set of support particlescontains component (b) and not component (c), and the second set ofsupport particles contains component (c) and not component (b). Anexample of such a catalyst is one in which the first set of supportparticles has a silica composition and the second set of supportparticles has a zeolite (e.g., Beta zeolite or ZSM-5 zeolite, typicallypartially or completely dealuminated) composition, and the first set ofsupport particles contains only copper and/or silver, while the secondset of the support particles contains only lanthanum and/or cerium.Another example of such a catalyst is one in which the first set ofsupport particles has a ZSM zeolite composition and the second set ofsupport particles has a Beta zeolite composition, and the first set ofsupport particles contains only copper and/or silver, while the secondset of support particles contains only lanthanum and/or cerium. Anotherexample of such a catalyst is one in which the first set of supportparticles has a silica composition and the second set of supportparticles has a zeolite (e.g., Beta zeolite or ZSM-5 zeolite, typicallypartially or completely dealuminated) composition, and the first set ofsupport particles contains only copper (and/or silver) and zinc, whilethe second set of support particles contains only lanthanum and/orcerium. Another example of such a catalyst is one in which the first setof support particles has a ZSM zeolite composition and the second set ofsupport particles has a Beta zeolite composition, and the first set ofsupport particles contains only copper (and/or silver) and zinc, whilethe second set of support particles contains only lanthanum and/orcerium. Another example of such a catalyst is one in which the first setof support particles has a silica composition and the second set ofsupport particles has a zeolite (e.g., Beta zeolite or ZSM-5 zeolite,typically partially or completely dealuminated) composition, and thefirst set of support particles contains only copper (and/or silver),while the second set of support particles contains only lanthanum(and/or cerium) and zinc. Another example of such a catalyst is one inwhich the first set of support particles has a ZSM zeolite compositionand the second set of support particles has a Beta zeolite composition,and the first set of support particles contains only copper (and/orsilver), while the second set of support particles contains onlylanthanum (and/or cerium) and zinc.

Compositions pertaining to the catalyst, as described above, can besynthesized by methods well known in the art. The method may incorporatethe metal ions homogeneously into the silica or zeolite support, whichmay include metal ions on surfaces of the zeolite. In particularembodiments, the catalyst described herein is prepared by a solid-stateion exchange method in which the silica or zeolite is physically mixed(e.g., by grinding) with one or more metal nitrate precursors, followedby calcining (e.g., at a temperature of 500-600° C.) for a suitableperiod of time (e.g., 1-12 hours). For purposes of the presentinvention, the zeolite being impregnated with nitrate precursors istypically a dealuminated zeolite. In other embodiments, the catalyst canbe prepared by, first, treating the silica or zeolite (which may or maynot be dealuminated) with one or more solutions containing salts of themetals to be loaded. The metal-containing solution may be contacted withthe silica or zeolite such that the solution is absorbed into the silicaor zeolite, preferably into the entire volume of the silica or zeolite.In one embodiment, the impregnating step is achieved by treating thesilica or zeolite with a solution that contains all of the metals to beloaded. In another embodiment, the impregnating step is achieved bytreating the silica or zeolite with two or more solutions, wherein thedifferent solutions contain different metals or combinations of metals.Each treatment of the silica or zeolite with an impregnating solutioncorresponds to a separate impregnating step. Typically, when more thanone impregnating step is employed, a drying and/or thermal treatmentstep is employed between the impregnating steps. The preparation of anumber of types of zeolites, including pillared forms of two-dimensionalzeolites, is described in, for example, W. J. Roth et al., Chem. Rev.,114, 4807-4837, 2014, the contents of which are herein incorporated byreference.

In another aspect, the present disclosure is directed to a method forconverting an alcohol to one or more olefinic compounds. In theconversion method described herein, an alcohol is catalyticallyconverted to one or more olefinic compounds (i.e., one or more“olefins”) by contacting the alcohol with a metal-loaded zeolitecatalyst at a suitable temperature (e.g., at least 100° C. and up to500° C.) to result in the alcohol being directly converted to the one ormore olefins. The alcohol is contacted with the catalyst by feeding analcohol feed material (which contains at least the alcohol, typically inaqueous solution) to any of the catalyst compositions described at aspecified elevated temperature, as further described below. As usedherein, the term “alcohol” refers to a single alcohol or a mixture oftwo or more alcohols. The term “olefinic compounds” (i.e., “olefins”)refers primarily to alkenes (e.g., C₃-C₁₂), which includes mono-enes anddienes (e.g., 1,3-butadiene). In some embodiments, alkenes (olefins) areherein considered to be distinct from 1,3-butadiene, in which case themethod may be considered to produce an alkene (olefinic) fraction alongwith co-production of a 1,3-butadiene fraction. Notably, the process isa direct conversion of the alcohol to the olefin fraction, wherein theterm “direct” indicates that any of the catalyst compositions describedabove, whether alone or admixed with a co-catalyst, converts the alcoholin the absence of a separate intermediate or final step that relies onanother catalyst to achieve the conversion.

The alcohol considered herein is generally of the formula R—OH, where Ris typically a straight-chained or branched alkyl group having at leastone or two carbon atoms and up to any number of carbon atoms, e.g., upto 3, 4, 5, or 6 carbon atoms. The alcohol is typically a primary orsecondary alcohol. Some examples of suitable alcohols include methanol,ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol,tert-butanol, n-pentanol, isopentanol, and n-hexanol. In someembodiments, the alcohol feed (starting) material contains at leastethanol, or ethanol in combination with one or more of the alcoholsprovided above. In some embodiments, the alcohol feed excludes any oneor more alcohols described above, such as methanol. In some embodiments,the alcohol feed includes or exclusively contains ethanol and/oralcohols with more carbon atoms than ethanol. The alcohol may also be orinclude a diol, such as ethylene glycol, propylene glycol, or2,3-butanediol. The alcohol feed may or may not also be accompanied byone or more other oxygen-containing molecules, which may or may not alsobe converted to the one or more olefinic compounds by the catalystdescribed in the present disclosure. The one or more otheroxygen-containing molecules may be, for example, acetone, acetaldehyde,acetoin, dimethyl ether, diethyl ether, and/or furfural. In someembodiments, any one or more of the oxygen-containing molecules listedabove may be in a trace amount (e.g., no more than or less than 1 wt %)or excluded from the feed containing the alcohol.

In the feed material, the alcohol can be in any concentration, includingpure (dry) alcohol, i.e., at or about 100% or in aqueous solution. Insome embodiments, the alcohol is in aqueous solution in a concentrationof no more than 50 vol %, 40 vol %, 30 vol %, 20 vol %, or 10 vol %. Insome embodiments, the alcohol considered herein, to be converted toolefins, is one that can be produced by a fermentation process (i.e., abio-alcohol). Most notable examples of bio-alcohols considered hereininclude ethanol, n-butanol, and isobutanol. In different embodiments,the alcohol is ethanol, butanol, or isobutanol, or a combinationthereof, as commonly found in fermentation streams. In particularembodiments, the alcohol is an aqueous solution of alcohol (i.e., thealcohol is a component of an aqueous solution), such as found infermentation streams.

The feed material may, in some embodiments, be a fermentation streamthat includes one or more alcohols therein as a component. Thefermentation stream may be directly contacted with the catalyst toconvert at least the one or more alcohols therein to an olefin fraction.The fermentation stream may be, for example, an acetone-butanol-ethanol(ABE) fermentation stream, 1-butanol/isobutanol stream, or a2,3-butanediol fermentation stream. In fermentation streams, the alcoholis typically in a concentration of no more than about 20% (vol/vol),15%, 10%, or 5%, wherein the term “about” generally indicates within±1%, 2%, 5%, or up to ±10% of the indicated value. The aqueous solutionof alcohol may contain the alcohol in any of the foregoing amounts. Insome embodiments, a fermentation stream or other alcoholic aqueoussolution derived from a fermentation stream is directly contacted withthe catalyst (typically, after filtration to remove solids) to effectthe conversion of the alcohol in the fermentation stream. In otherembodiments, the fermentation stream or other alcoholic aqueous solutionis concentrated in alcohol (for example, of at least or up to 20%, 30%,40%, or 50%) before contacting the fermentation stream with thecatalyst. In yet other embodiments, alcohol in the fermentation streamor other alcoholic aqueous solution is selectively removed from thealcoholic aqueous solution, such as by distillation, to produce asubstantially pure form of alcohol as the feedstock (e.g., aconcentration of at least 90% or 95% of alcohol). In still otherembodiments, the alcohol is completely dewatered into 100% alcoholbefore contacting with the catalyst.

The olefinic compounds herein produced by the catalytic conversion ofalcohols generally include a range of alkenes (e.g., at least propene,butenes, and C₅-C₁₀ alkenes) and/or dienes (e.g., 1,3-butadiene,1,3-hexadiene, or 1,5-hexadiene). The term “alkenes,” as used herein,includes at least hydrocarbon compounds containing a singlecarbon-carbon double bond, and may or may not also include olefins withtwo or more carbon-carbon double bonds, e.g., 1,3-butadiene or1,3,5-hexatriene. Some examples of alkenes containing four or morecarbon atoms (i.e., C₄₊ alkenes, or more specifically, C₄₋₁₀ alkenes)include 1-butene, 2-butene, 1-pentene, cis-2-pentene, trans-2-pentene,isopentene (3-methyl-1-butene), 1-hexene, cis-2-hexene, trans-2-hexene,cis-3-hexene, trans-3-hexene, isohexene (4-methyl-1-pentene),3-methyl-1-pentene, 3,4-dimethyl-1-pentene, 1-heptene, isoheptene(5-methyl-1-hexene), 4-methyl-1-hexene, 1-octene,2,4,4-trimethyl-1-pentene, 1-nonene, cis-3-nonene, trans-3-nonene,1-decene, cis-4-decene, and trans-4-decene. The process described hereinmay also be capable of producing a minor fraction of alkenes having acarbon number greater than 10, i.e., C₁₀₊ alkenes, such as C₁₁ and C₁₂alkenes. Notably, although in some embodiments, non-olefin product(e.g., paraffins, aromatics, and/or aldehydes) may be produced alongsidethe olefin fraction, the olefin fraction typically represents at leastor greater than 80, 85, 90, 95, 96, 97, 98, 99, or 100 vol % of thetotal product volume.

In the process, a suitable reaction temperature is employed duringcontact of the one or more alcohols with the catalyst. Generally, thereaction temperature is at least 100° C. and up to 500° C. In differentembodiments, the reaction temperature is precisely or about, forexample, 100° C., 125° C., 150° C., 175° C., 200° C., 225° C., 250° C.,275° C., 300° C., 325° C., 350° C., 375° C., 400° C., 425° C., 450° C.,475° C., or 500° C., or a temperature within a range bounded by any twoof the foregoing exemplary temperatures, e.g., 100° C.-500° C., 200°C.-500° C., 300° C.-500° C., 350° C.-500° C., 400° C.-500° C., 100°C.-450° C., 200° C.-450° C., 250° C.-450° C., 300° C.-450° C., 100°C.-400° C., 200° C.-400° C., 300° C.-400° C., 100° C.-300° C., or 200°C.-300° C. Generally, ambient (i.e., normal atmospheric) pressure ofabout 1 atm is used in the method described herein. However, in someembodiments, an elevated pressure may be used. For example, in someembodiments, the pressure may be elevated to, for example, 1.5, 2, 3, 4,or 5 atm.

In some embodiments, the conversion process is conducted under ahydrogen gas atmosphere, in the substantial or complete absence ofoxygen, and wherein the hydrogen gas may be present in an amount of atleast 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100 vol % of theatmosphere. The hydrogen gas may or may not be admixed with one or moreinert gases (e.g., nitrogen and/or argon). In other embodiments, theconversion process is conducted under an inert or partial inertatmosphere.

Ethylene is typically produced in the above described process in anamount of no more than 5 vol % of the olefin fraction. In differentembodiments, depending on, inter alia, the catalyst composition andprocessing temperature, ethylene can be produced in an amount of no morethan or less than, for example, 5, 4.5, 4, 3.5, 3, 2.5, 2, 1.5, 1, 0.5,0.2, or 0.1 vol %, or an amount within a range bounded by any two of theforegoing values (e.g., 0.1-5 vol % or 0.1-2 vol %). In someembodiments, ethylene is not produced.

Propene (propylene) is typically produced in the above described processin an amount of no more than 25 vol % of the olefin fraction. Indifferent embodiments, depending on, inter alia, the catalystcomposition and processing temperature, propene can be produced in anamount of no more than or less than, for example, 25, 20, 15, 10, 5, 2,or 1 vol %, or an amount within a range bounded by any two of theforegoing values (e.g., 1-25 vol %, 1-20 vol %, 1-15 vol %, or 1-10 vol%).

Butenes are typically produced in the above described process in anamount of least vol % of the olefin fraction. In different embodiments,depending on, inter alia, the catalyst composition and processingtemperature, butenes may be produced in an amount of at least or greaterthan, for example, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80,85, or vol %, or an amount within a range bounded by any two of theforegoing values (e.g., 20-vol %, 30-80 vol %, 40-80 vol %, 20-85 vol %,30-85 vol %, 40-85 vol %, 20-90 vol %, 30-vol %, or 40-90 vol %).

Olefins containing at least three carbon atoms (i.e., C₃₊ olefins) maybe present in the olefin fraction in an amount of at least 10 vol %. Indifferent embodiments, depending on, inter alia, the catalystcomposition and processing temperature, C₃₊ olefins may be produced inan amount of at least or greater than, for example, 10, 15, 20, 25, 30,35, 40, 45, 50, 55, 65, 70, 75, 80, 85, 90, 95, 96, 97, or 98 vol %, oran amount within a range bounded by any two of the foregoing values(e.g., 10-98 vol %, 20-98 vol %, 30-98 vol %, 40-98 vol %, vol %, 60-98vol %, 70-98 vol %, and 80-98 vol %).

Olefins containing at least four carbon atoms (i.e., C₄₊ olefins) may bepresent in the olefin fraction in an amount of at least 10 vol %. Indifferent embodiments, depending on, inter alia, the catalystcomposition and processing temperature, C₄₊ olefins may be produced inan amount of at least or greater than, for example, 10, 15, 20, 25, 30,35, 40, 45, 50, 55, 65, 70, 75, 80, 85, 90, 95, 96, 97, or 98 vol %, oran amount within a range bounded by any two of the foregoing values(e.g., 10-98 vol %, 20-98 vol %, 30-98 vol %, 40-98 vol %, vol %, 60-98vol %, 70-98 vol %, and 80-98 vol %).

Olefins containing at least five carbon atoms (i.e., C₅₊ olefins) may bepresent in the olefin fraction in an amount of at least 5 vol %. Indifferent embodiments, depending on, inter alia, the catalystcomposition and processing temperature, C₅₊ olefins may be produced inan amount of at least or greater than, for example, 5, 10, 15, 20, 25,30, 35, 40, 45, 50, 55, 65, or 70 vol %, or an amount within a rangebounded by any two of the foregoing values (e.g., 5-50 vol %, 10-50 vol%, 5-40 vol %, 10-40 vol %, 5-30 vol %, and 10-30 vol %).

Olefins containing at least six carbon atoms (i.e., C₆₊ olefins) may bepresent in the olefin fraction in an amount of at least 3 vol %. Indifferent embodiments, depending on, inter alia, the catalystcomposition and processing temperature, C₆₊ olefins may be produced inan amount of at least or greater than, for example, 3, 4, 5, 10, 15, 20,25, 30, 35, 40, 45, 55, 60, 65, or 70 vol %, or an amount within a rangebounded by any two of the foregoing values (e.g., 3-50 vol %, 4-50 vol%, 5-50 vol %, 3-40 vol %, 4-40 vol %, 5-40 vol %, 3-30 vol %, 4-30 vol%, 5-30 vol %, 3-20 vol %, 4-20 vol %, 5-20 vol %, 3-10 vol %, 4-10 vol%, or 5-10 vol %).

Olefins containing at least seven carbon atoms (i.e., C₇₊ olefins) maybe present in the olefin fraction in an amount of at least 1 vol %. Indifferent embodiments, depending on, inter alia, the catalystcomposition and processing temperature, C₇₊ olefins may be produced inan amount of at least or greater than, for example, 1, 2, 3, 4, 5, 10,15, 20, 25, 30, 35, 40, 50, 55, 60, 65, or 70 vol %, or an amount withina range bounded by any two of the foregoing values (e.g., 1-40 vol %,2-40 vol %, 3-40 vol %, 4-40 vol %, 5-40 vol %, 1-30 vol %, 2-30 vol %,3-30 vol %, 4-30 vol %, 5-30 vol %, 1-20 vol %, 2-20 vol %, 3-20 vol %,4-20 vol %, 5-20 vol %, 1-10 vol %, 2-10 vol %, 3-10 vol %, 4-10 vol %,or 5-10 vol %).

Olefins containing at least eight carbon atoms (i.e., C₈₊ olefins) maybe present in the olefin fraction in an amount of at least 1 vol %. Indifferent embodiments, depending on, inter alia, the catalystcomposition and processing temperature, C₈₊ olefins may be produced inan amount of at least or greater than, for example, 1, 2, 3, 4, 5, 10,15, 20, 25, 30, 35, 40, or 50 vol %, or an amount within a range boundedby any two of the foregoing values (e.g., 1-30 vol %, 2-30 vol %, 3-30vol %, 4-30 vol %, 5-30 vol %, 1-20 vol %, 2-20 vol %, 3-20 vol %, 4-20vol %, 5-20 vol %, 1-10 vol %, 2-10 vol %, 3-10 vol %, 4-10 vol %, 5-10vol %, 1-5 vol %, 2-5 vol %, or 1-3 vol %).

Alkanes (e.g., ethane, propane, butanes, pentanes, and paraffins) may ormay not be produced in the process described above along with the olefinfraction. If alkanes (or specifically, paraffins) are also produced,they are typically present in an amount of no more than 5 vol % of thetotal volume of products produced (i.e., wherein total products includesolefins and non-olefins). In different embodiments, depending on, interalia, the catalyst composition and processing temperature, alkanes (ormore specifically, paraffins) may be produced in an amount of no morethan or less than, for example, 1, 2, 3, 4, or 5 vol %, or an amountwithin a range bounded by any two of the foregoing values (e.g., 1-5 vol%, 1-4 vol %, 1-3 vol %, or 1-2 vol %).

Aromatics (e.g., benzene, toluenes, and/or xylenes) may or may not beproduced in the process described above along with the olefin fraction.If aromatics are also produced, they are typically present in an amountof no more than 2 vol % of the total volume of products produced (i.e.,wherein total products includes olefins and non-olefins). In differentembodiments, depending on, inter alia, the catalyst composition andprocessing temperature, aromatics may be produced in an amount of nomore than or less than, for example, 0.1, 0.2, 0.5, 1, 1.5, or 2 vol %,or an amount within a range bounded by any two of the foregoing values(e.g., 0.1-2 vol %, 0.1-1 vol %, or 0.1-0.5 vol %).

Oxygenated product may or may not also be produced in the processdescribed above along with the olefin product. The oxygenated productmay be or include, for example, one or more aldehydes (e.g.,acetaldehyde, propionaldehyde, and/or butyraldehyde) or ketones (e.g.,acetone, butanones, pentanones, and diones). If oxygenated product isalso produced, it is typically present in an amount of no more than 3vol % of the total volume of products produced (i.e., wherein totalvolume of products includes olefins and non-olefins). In differentembodiments, depending on, inter alia, the catalyst composition andprocessing temperature and atmosphere, oxygenated product may beproduced in an amount of no more than or less than, for example, 0.1,0.2, 0.5, 1, 1.5, 2, 2.5, or 3 vol %, or an amount within a rangebounded by any two of the foregoing values (e.g., 0.1-3 vol %, 0.1-2 vol%, 0.1-1 vol %, or 0.1-0.5 vol %).

The catalyst and reactor can have any of the designs known in the artfor catalytically treating a fluid or gas at elevated temperatures, suchas a fluidized bed reactor. The process may be in a continuous or batchmode. In particular embodiments, the alcohol-containing feed is injectedinto a heated reactor such that the alcohol is quickly volatilized intogas, and the gas passed over the catalyst. In some embodiments, thereactor design includes a boiler unit and a reactor unit if thefermentation stream is used directly as a feedstock withoutpurification. The boiler unit is generally not needed if thefermentation stream is distilled to concentrate ethanol because thedistillation process removes the dissolved solids in the fermentationstreams. The boiler unit volatilizes liquid feedstock into gases priorto entry into the reactor unit and withholds dissolved solids.

To effect further conversion of the olefins to a fossil fuel (e.g., ajet fuel), the olefinic compounds may be reacted with one or moreadditional catalysts known in the art capable of such transformation,such as oligomerization. The additional catalyst may be, for example, azeolite (e.g., H-BEA, H-ZSM-5, MCM, H-ZSM-22, or H-ZSM-57), amorphousaluminosilicate, sulfonic acid ion-exchange resin (e.g., Amberlyst® 15,Amberlyst® 35, Amberlyst® 36, Purolite®, Dowex®, Lewatit®), or solidphosphoric acid. The conditions of the reaction may be, for example,100-500° C. (or more particularly, 70-350° C.), 1-60 atm, a weighthourly space velocity (WHSV) of 0.1 h⁻¹ to 20 h⁻¹, and an inert orhydrogen carrier gas. The foregoing catalysts and conditions aregenerally suited for a dimerization, oligomerization, ordehydrocyclization process. However, the process may also include ahydrogenation (hydrotreating) process, which may employ an oxidecatalyst (e.g., Al₂O₃, TiO₂, CeO₂, or ZrO₂) coated or impregnated withplatinum (Pt), nickel (Ni), rhodium (Rh), ruthenium (Ru) or other noblemetal or precious metal. In some embodiments, the oligomerization andhydrogenation occur simultaneously, while in other embodiments, thehydrogenation is performed after the oligomerization.

In some embodiments, the method converts an alcohol to a hydrocarbonfuel, such as jet fuel and/or diesel fuel, by: (i) producing the one ormore olefinic compounds (olefin fraction) according to the methoddescribed above, (ii) oligomerizing the olefinic compounds to produce anoligomerized product, and (iii) hydrogenating (hydrotreating) theoligomerized product. Oligomerization and hydrogenation catalysts foreffecting steps (ii) and (iii), respectively, are well known in the art.

The oligomerization process may more particularly entail, e.g.,contacting the olefin fraction with an oligomerization catalyst at atemperature of at least 40° C. and up to 400° C. to result in anoligomerized product, e.g., a C₆ ⁺, C₇ ⁺, or C₈ ⁺ partially unsaturatedfraction. In different embodiments, step (ii) employs a temperature ofprecisely or about, for example, 50° C., 60° C., 70° C., 80° C., 90° C.,100° C., 150° C., 200° C., 250° C., 300° C., 350° C., or 400° C., or atemperature within a range bounded by any two of the foregoing values,e.g., 40-350° C., 40-300° C., 40-250° C., 40-200° C., 40-150° C.,50-400° C., 50-350° C., 50-300° C., 50-250° C., 50-200° C., 50-150° C.,80-400° C., 80-350° C., 80-300° C., 80-250° C., 80-200° C., or 80-150°C. Oligomerization catalysts are well known in the art, as evidenced in,for example, A. Lacarriere et al., ChemSusChem, 5, 1787-1792 (2012), thecontents of which are herein incorporated by reference. As well known,oligomerization catalysts can be divided into two main categories: acidcatalysts, particularly suited for the oligomerization of C₃ or higherolefins, and nickel-containing catalysts (e.g., nickel complexes ornickel-exchanged zeolite), particularly suited for ethyleneoligomerization. Some examples of oligomerization catalysts include acidzeolite catalysts (e.g., H-BEA, H-ZSM-5, MCM-41, H-ZSM-22, or H-ZSM-57),metal-containing zeolite catalysts (e.g., nickel- and aluminum-exchangedzeolites, such as NiMCM-41, AlMCM-41, NiMCM-48, and AlMCM-48), amorphousaluminosilicate, sulfonic acid ion-exchange resins (e.g., Amberlyst® 15,Amberlyst® 35, Amberlyst® 36, Purolite®, Dowex®, Lewatit®), sulfatedalumina, and solid phosphoric acid. The oligomerization process mayemploy standard pressure (about 1 atm) or an elevated pressure (e.g., atleast or above 10, 20, 30, or 50 atm). The oligomerization process maybe conducted under an inert gas atmosphere. At the completion of orduring the oligomerization process in step (ii), the second paraffinfraction and C₇ ⁺ partially unsaturated (oligomeric) fraction areseparated from each other by means well known in the art, and the firstand second paraffin fractions are combined to result in a total C₃-C₆paraffin fraction.

The hydrogenation process may more particularly entail, e.g., contactingthe partially unsaturated fraction with a precious metal-containinghydrogenation catalyst in the presence of hydrogen gas at a temperatureof at least 100° C. and up to 500° C. (or precisely or about 100° C.,150° C., or 200° C. and up to precisely or about 250° C., 300° C., 350°C., 400° C., 450° C., 500° C.) to produce a jet fuel or dieselhydrocarbon fraction, wherein the jet fuel or diesel hydrocarbonfraction contains a C₆ ⁺, C₇ ⁺, or C₈ ⁺ paraffin fraction withsubstantially no olefin or aromatic fraction. Precious metal-containinghydrogenation catalysts are well known in the art, e.g., Pt or Pd on anoxide support, such as alumina (Al₂O₃). The hydrotreating process mayemploy standard pressure (about 1 atm) or an elevated pressure (e.g., atleast or above 1, 2, 5, 10, 20, 30, 40, or 50 atm, or a range therein,e.g., 1-5 atm, 2-5 atm, 1-10 atm, 2-10 atm, 1-30 atm, or 2-30 atm), andmay be conducted under a standard air atmosphere or an inert gas (e.g.,nitrogen or argon) atmosphere. In some embodiments, the paraffinfraction includes or exclusively contains alkanes having at least eight,nine, or ten carbon atoms and up to twelve, fourteen, sixteen, eighteen,or twenty carbon atoms, e.g., a range of C₈-C₂₀, C₈-C₁₈, C₈-C₁₆, C₈-C₁₄,C₉-C₂₀, C₉-C₁₈, C₉-C₁₆, C₉-C₁₄, C₁₀-C₂₀, C₁₀-C₁₈, C₁₀-C₁₆, or C₁₀-C₁₄alkanes.

The method described above produces a mainly liquid hydrocarbon fuel.Such fuel refers to a mixture of hydrocarbon compounds useful as a fuelor as a blendstock in a fuel. The mixture of hydrocarbon compoundsproduced herein substantially corresponds (e.g., in composition and/orproperties) to a known petrochemical fuel, such as petroleum, or afractional distillate of petroleum. Some examples of petrochemical fuelsinclude jet fuel (i.e., jet propellant, such as JP-8), gasoline,kerosene, and diesel. Although aromatics (particularly benzene) may bepresent in the hydrocarbon mixture, their presence may be minimized bymethods known in the art to adhere to current fuel standards. The rawhydrocarbon product may also be fractionated by distillation intodifferent fuel grades, each of which is known to be within a certainboiling point range. Another advantage of the above described method isits ability to produce such fuel grades in the substantial absence ofcontaminants (e.g., mercaptans) normally required to be removed duringthe petroleum refining process. Moreover, by appropriate adjustment ofthe catalyst and processing conditions, a select distribution ofhydrocarbons can be obtained.

Any of the catalysts described above can also be mixed with or affixedonto a support material suitable for the conditions of the conversionreaction. The support material may be a powder (e.g., having any of theabove particle sizes), granular particles (e.g., 0.5 mm or greaterparticle size), a bulk material, such as a honeycomb monolith of theflow-through type, a plate or multi-plate structure, or corrugated metalsheets. If a honeycomb structure is used, the honeycomb structure cancontain any suitable density of cells. For example, the honeycombstructure can have 100, 200, 300, 400, 500, 600, 700, 800, or 900 cellsper square inch (cells/in²) (or from 62-140 cells/cm²) or greater. Thesupport material is generally constructed of a refractory composition,such as those containing cordierite, mullite, alumina (e.g., α-, β-, orγ-alumina), or zirconia, or a combination thereof. Honeycomb structures,in particular, are described in detail in, for example, U.S. Pat. Nos.5,314,665, 7,442,425, and 7,438,868, the contents of which areincorporated herein by reference in their entirety. When corrugated orother types of metal sheets are used, these can be layered on top ofeach other with catalyst material supported on the sheets such thatpassages remain that permit the flow of the liquid or gas containing theorganic species undergoing conversion. The layered sheets can also beformed into a structure, such as a cylinder, by winding the sheets.

Depending on the final composition of the hydrocarbon product, theproduct can be directed to a variety of applications, including, forexample, as precursors for plastics, polymers, and fine chemicals. Theprocess described herein can advantageously produce a range of olefinand non-olefin compounds that differ in any of a variety ofcharacteristics, such as molecular weight (i.e., hydrocarbon weightdistribution), degree of saturation or unsaturation (e.g., alkane toalkene ratio), and level of branched or cyclic isomers. The processprovides this level of versatility by appropriate selection of, forexample, composition of the catalyst, amount of catalyst (e.g., ratio ofcatalyst to alcohol precursor), processing temperature, atmospherecomposition, and flow rate (e.g., LHS V).

In some embodiments, the conversion method described above is integratedwith a fermentation process, wherein the fermentation process producesthe alcohol used as feedstock for the conversion process. In oneembodiment, the fermentation process is a biomass fermentation processthat produces mainly ethanol or ethanol in combination with butanol fromstarches and sugars. In another embodiment, the fermentation process isa acetone-butanol-ethanol (ABE) fermentation process, as well known inart. In another embodiment, the fermentation process is a 2,3-butanediolprocess (which may also produce acetoin), as well known in the art. Bybeing “integrated” is meant that alcohol produced at a fermentationfacility or zone is sent to and processed at a conversion facility orzone that performs the conversion process described above. Preferably,in order to minimize production costs, the fermentation process is inclose enough proximity to the conversion facility or zone, or includesappropriate conduits for transferring produced alcohol to the conversionfacility or zone, thereby not requiring the alcohol to be shipped. Inparticular embodiments, the fermentation stream produced in thefermentation facility is directly transferred to the conversionfacility, generally with removal of solids from the raw stream(generally by filtration or settling) before contact of the stream withthe catalyst.

In some embodiments, the fermentation process is performed in anautonomous fermentation facility, i.e., where saccharides, producedelsewhere, are loaded into the fermentation facility to produce alcohol.In other embodiments, the fermentation process is part of a largerbiomass reactor facility, i.e., where biomass is decomposed intofermentable saccharides, which are then processed in a fermentationzone. Biomass reactors and fermentation facilities are well known in theart. Biomass generally refers to lignocellulosic matter (i.e., plantmaterial), such as wood, grass, leaves, paper, corn husks, sugar cane,bagasse, and nut hulls. Generally, biomass-to-ethanol conversion isperformed by 1) pretreating biomass under well-known conditions toloosen lignin and hemicellulosic material from cellulosic material, 2)breaking down cellulosic material into fermentable saccharide materialby the action of a cellulase enzyme, and 3) fermentation of thesaccharide material, typically by the action of a fermenting organism,such as suitable yeast, to produce one or more alcohols.

In other embodiments, the alcohol is produced from a more direct sugarsource, such as a plant-based source of sugars, such as sugar cane or agrain starch (such as corn starch). Ethanol production via corn starch(i.e., corn starch ethanol) and via sugar cane (i.e., cane sugarethanol) currently represent some of the largest commercial productionmethods of ethanol. Integration of the instant conversion process withany of these large scale ethanol production methods is contemplatedherein.

Examples have been set forth below for the purpose of illustration andto describe certain specific embodiments of the invention. However, thescope of this invention is not to be in any way limited by the examplesset forth herein.

Example 1

A method is described below for converting ethanol to liquid hydrocarbonfuels, in which the method includes one-step ethanol conversion to C₃₊and/or C₄₊ olefins with significant C₅₊ olefins. The method mayco-produce 1,3-butadiene, and may optionally be followed byoligomerization and hydrogenation to form gasoline, diesel and jetfractions, as shown in FIG. 1A.

In the first step, ethanol is converted to C₃₊ olefins in one stepwithout ethanol dehydration step. This step is achieved by use of acopper-modified Lewis acid catalyst, e.g., a Cu-modified La-based Betazeolite (e.g., Cu—Zn—La/Beta) or Cu/SiO₂-Zn/La/Beta. Particularlydemonstrated herein is ethanol conversion to C₃₊ olefins over threeLa-based catalysts, including Cu—Zn—La/Beta catalyst, Cu/SiO₂-Zn/La/Betacatalyst, and Cu/SiO₂-La/B eta at 350° C. and ambient pressure under ahydrogen environment. Ethanol conversion of >97% was achieved with >80%C₃₊ olefins selectivity. C₅₊ olefins selectivity can be as high as ca.62% or higher. For the second step, these C₃₊ olefins can be readilyoligomerized to middle distillate-range hydrocarbons over solid acidcatalysts, e.g., zeolites. The results are shown in Table 1 below.

TABLE 1 One-step catalytic conversion of ethanol over La-based catalystsCu/SIO₂—La/BEA Cu/SIO₂—Zn/La/BEA Cu—Zn—La/BEA Temperature (° C.) 350Weight of catalyst (g) 0.3005 0.3032 0.3036 Ethanol flow rate (mL/h)0.2015 0.2015 0.2015 H₂ flow rate (mL/h) 18.6 18.6 18.6 WHSV (h⁻¹) 0.530.52 0.52 H₂ concentration (%) 93.1 93.1 93.1 Ethanol concentration (%)6.9 6.9 6.9 Acetaldehyde selectivity (%) 12.4 1.9 4.9 Ethyleneselectivity (%) 2.1 2.9 4.2 Propene selectivity (%) 0.4 1.1 1.8 Butenesselectivity (%) 25 31.7 37.6 C₅₊ olefins selectivity (%) 54.6 61.9 48.8Total olefins selectivity (%) 82.2 97.6 92.4 Oxygenates selectivity (%)17.5 1.9 7.2 Paraffins selectivity (%) 0.4 0.5 0.4 C₃₊ olefinsselectivity (%) 80.1 94.7 88.2

Carbon selectivity

indicates data missing or illegible when filed

The method is also directed to conversion of ABE or butanol to liquidhydrocarbon fuels in which the method includes one-pot ABE conversion toC₃₊ olefins. The method may further include oligomerization followed byhydrotreating, as shown in FIG. 1B.

In the first step, ABE or butanol is converted to C₃₊ olefins in one potwithout separating acetone, butanol, and ethanol and without completeremoval of water from the fermentation broth. This step is achieved byuse of a copper-modified Lewis acid catalysts, e.g., Cu-modifiedLa-based Beta zeolite (e.g., Cu—Zn—La/Beta or Cu/SiO₂-Zn/La/Beta).Particularly demonstrated herein is ABE conversion to C₃₊ olefins overCu—Zn—La/BEA catalyst at 350° C. and ambient pressure under a hydrogenenvironment, wherein ca. 99.8% conversion of ABE is achieved with ca.97% C₃₊ olefins selectivity and ca. 43.5% C₅₊ olefins, 26.5% C₇₊olefins. For the second step, these C₅₊ olefins (especially C₇₊ olefins)can be readily oligomerized to middle distillate-range hydrocarbons oversolid acid catalysts, e.g., zeolites. The results are shown in Table 2below.

TABLE 2 One-step catalytic conversion of Acetone-Butanol-Ethanol (3:6:1,mass ratio) over Cu—Zn—La/BEA catalysts Cu—Zn—La/BEA Temperature (° C.)350 Carrier gas H₂ Conversion (%) 99.82 Ethylene Sel (%) 0.62 PropeneSel (%) 19.43 Butenes Sel (%) 34.24 C₅ Olefins Sel (%) 11.45 C₆ OlefinsSel (%) 5.56 C₇₊ Olefins Sel (%) 26.51 C₅₊ Olefins Sel (%) 43.53 TotalOlefins Sel (%) 97.82 Oxygenates Sel (%) 1.12 Paraffins Sel (%) 1.24 C₃₊olefins Sel (%) 97.2

Carbon selectivity

indicates data missing or illegible when filed

The catalyst and method described herein for converting ethanol to C₃₊olefins offers numerous benefits, including: 1) avoidance of theadditional endothermic ethanol dehydration step; 2) avoidance ofenergy-intensive ethylene separation step by significantly reducingethylene production; 3) reduction in the number of key ethanolconversion steps from four/five to three, offering a great opportunityfor reduction of CapEx and OpEx; 4) minimization of light paraffinsformation and avoidance of aromatics formation during the ethanolconversion step, which offers the potential to increase the liquidhydrocarbon fuel yield. Moreover, ethanol can be directly converted toC₄₊ olefins with high selectivity of C₆ and C₈ olefins. These olefinmixtures can be oligomerized to middle-range distillate fuels with theoption to produce a higher fraction of jet or diesel fuel.

The catalyst and method described herein also provides a single-step ABEor butanol conversion to C₃₊ olefins with >40% C₅₊ olefins andsignificant amount of C₇₊ olefins, which can be readily upgraded to jetor diesel-range hydrocarbons via oligomerization. This technologypermits direct feeding of aqueous ABE streams without the need forremoval of water and separation of ABE products, and this dramaticallyreduces the cost of the conversion process. The method can also providesubstantially improved product yields. An added benefit is that the ABEconversion step is achieved using inexpensive earth-abundant catalysts,as described above, and this will help the process becomecost-competitive with distillate fossil fuel production. The method canalso advantageously be used for converting butanol or butanolfermentation mixture to middle distillate fuels.

Example 1. Cu—Ce/Beta Catalyst for Ethanol Conversion to Olefins

Cu—Ce/Beta Catalyst Synthesis

H-BEA (SAR=11.5) was obtained by calcinating NH₄-Beta (CP814E, Zeolyst)under 823 K under 1.7 cm³ g⁻¹cat s⁻¹ air for 12 h. 10 g H-Beta was mixedwith 250 mL nitric acid (69% to 70%) in a sealed container at 353 K with500 rpm stirring for 16 h. The solid was centrifuged and washed with DIwater until pH is close to 9. The washed powder was dried under 353 K inan oven overnight to remove the remaining water and acid. The sample waslabeled as DeAl-Beta as the support for metal loading.

DeAl-Beta was mixed with copper nitrate trihydrate and cerium nitratehexahydrate in the mortar and ground for 20 min. The mixed powder washomogeneous light green with no blue dots. The mixture was calcinated to823 K with 1 K/min ramping rate and held for 6 h under 13.3 cm³ g⁻¹cats⁻¹ air to allow a complete decomposition of metal precursors andhomogeneous distribution of metal species. The as-synthesized catalystshave 1 wt % Cu loading, along with 7 wt % and 11.6 wt % Ce loading, andhave a light yellow color. The notation “7Ce” and “11.6Ce” is usedherein as a shorthand to denote 7 wt % and 11.16 wt % of Ce in thecatalyst. The catalysts produced in this experiment may then beexpressed as Cu-7Ce/Beta and Cu-11.6Ce/Beta.

Cu—Ce/Beta Catalyst Testing

The reaction was carried out in a tubular quartz reactor with afixed-bed configuration in a vertical tubular furnace. Typically, 0.3 gcatalysts were treated in situ by heating at 5 K min⁻¹ to 673 K and for1 h under 1.2 cm³ g⁻¹cat s⁻¹ He to remove adsorbed species. Aftercooling down to 623 K, the catalyst was reduced under 1.44 cm³ g⁻¹cats⁻¹ pure H₂ for 30 min. Flow rates of He and H₂ were controlled usingmass flow controllers. Ethanol was delivered using syringe pumps andwere evaporated inside the ⅛″ stainless steel transfer lines. The typesand the concentrations of the reactants and the products in stream weremeasured by a gas-chromatograph with thermal conductivity detector (TCD)and a flame ionization detector (FID). A gas chromatographmass-spectrometer (GC-MS) was used to determine the peak position ofreactants and products.

Catalytic Performance

More than 97% ethanol conversion was observed over both Cu-7Ce/Beta andCu-11.6Ce/Beta catalysts at 623 K, ethanol weight hourly space velocity(WHSV) of 0.52 h⁻¹, 7.1 kPa ethanol balanced with H₂ (total pressure101.3 kPa). The primary products were butenes and C₅₊ olefins with avery small amount of propene. The selectivities of total C₃₊ olefinswere 82% and 81% for Cu-7Ce/Beta and Cu-11.6Ce/Beta, respectively. Smallamounts of acetaldehyde and ethylene were also observed. The results aregraphically presented in FIG. 2 .

Example 2. Cu—La/Beta Catalyst for Ethanol Conversion to Olefins

The DeAl-Beta support was prepared using the same procedure asExample 1. The metal loading procedure is also similar except for theuse of lanthanum nitrate hexahydrate in place of cerium nitratehexahydrate. The nominal loading of Cu was 1 wt %, while the La loadingwas varied at 1, 3, 7, and 15 wt % for the catalysts Cu-1La/Beta,Cu-3La/Beta, Cu-7La/Beta, and Cu-15La/Beta, respectively. Thesecatalysts were tested in the same reactor setup and under the sameconditions as the Cu—Ce/Beta catalysts in Example 1.

Ethanol conversions over all these catalysts were above 95%. Over eachcatalyst, the observed products include acetaldehyde, ethylene, propene,butenes and C₅₊ olefins. Both acetaldehyde and ethylene selectivitiesdecreased as the La loading increased from 1 wt % to 15 wt %. Theethylene selectivity was as low as 3% when the La loading was 15 wt %.Propene selectivity was observed to be below 2% over all thesecatalysts. Butene selectivity was maximized at 38% on Cu-3La/Beta, whilemaximum C₅₊ olefins (54%) was observed over Cu-7La/Beta. The maximum C₃₊olefin selectivity was 85% with primarily butenes and C₅₊ olefins. Theresults are graphically presented in FIG. 3 .

Example 3. Cu/Silica+7La/Beta Catalyst for Ethanol Conversion to Olefins

The DeAl-Beta support was prepared using the same procedure asExample 1. The metal loading procedure for La/Beta was also similar toExample 1 except for the use of lanthanum nitrate hexahydrate in placeof cerium nitrate hexahydrate. The nominal La loading was 7 wt %.Cu-silica (1 wt %) was synthesized using the same method (copper nitratetrihydrate as Cu source) on commercially available silica(Sigma-Aldrich, pore size 1.5 nm, pore volume 1.15 cm³ g⁻¹). These twocatalysts were physically mixed using a weight ratio of 1:1, and testedin the same reactor setup and under the same conditions as theCu—Ce/Beta catalysts in Example 1.

Catalytic Performance

The physical mixture of Cu/Silica+7La/Beta catalyst was tested attemperatures of 623 K to 673 K. As the temperature increased, ethanolconversion increased from 92% to 100%. Acetaldehyde selectivity droppedsignificantly from 24% to 3.9%. Both ethylene and propene selectivitieswere much lower than 10%. Maximum butene selectivity and C₅₊ olefinselectivity were 52% and 39%, respectively. C₃₊ selectivity reached amaximum (87%) at 673 K. The results are shown in Table 3 below.

TABLE 3 Ethanol conversion and product selectivities over Cu/Silica +7La/Beta catalyst at different reaction temperatures Temp. WHSVSelectivity (K) (h⁻¹) Conv. Acetaldehyde C₂ ⁼ C₃ ⁼ C₄ ⁼ Butadiene C₅₊ ⁼C₃₊ ⁼ 623 0.53 92 24 1.9 0.4 22 0.1 39.2 61.6 648 0.53 97 10 4.4 2.9 511.0 27.0 80.5 673 0.53 100 3.9 6.0 4.0 52 0.3 31.2 87.0 Reactionconditions: 101.3 kPa, WHSV = 0.52 h⁻¹, 7.1 kPa ethanol balanced withH₂.

Example 4. Cu/Silica+Zn-La/Beta Catalyst for Ethanol Conversion toOlefins

The DeAl-Beta support was prepared using the same procedure asExample 1. The metal loading procedure for Zn—La/Beta was similar toExample 1 except for the use of zinc nitrate hexahydrate and lanthanumnitrate hexahydrate in place of cerium nitrate hexahydrate. The nominalZn and La loadings were 2 wt % and 7 wt %, respectively. Cu-silica (1 wt%) was synthesized using same method (copper nitrate trihydrate as Cusource) on commercially available silica (Sigma-Aldrich, pore size 1.5nm, pore volume 1.15 cm³ g⁻¹). These two catalysts were physically mixedusing a weight ratio of 1:1, and tested in the same reactor setup andunder the same conditions as the Cu—Ce/Beta catalysts in Example 1.

Catalytic Performance

The physical mixture of Cu/Silica+Zn-La/Beta catalyst was tested attemperatures of 623 K to 673 K. As temperature increased, ethanolconversion increased from 94% to 100%. Acetaldehyde selectivity droppedsignificantly from 18% to 3.1%. Both ethylene and propene selectivitieswere much lower than 10%. Maximum butene selectivity and C₅₊ olefinselectivity were 45% and 44%, respectively. C₃₊ selectivity reached amaximum (86%) at 673 K. The results are shown in Table 4 below.

TABLE 4 Ethanol conversion and product selectivities over Cu/Silica +Zn—La/Beta catalyst at different reaction temperatures Temp. WHSVSelectivity (K) (h⁻¹) Conv. Acetaldehyde C₂ ⁼ C₃ ⁼ C₄ ⁼ Butadiene C₅₊ ⁼C₃₊ ⁼ 623 0.52 94 18 3.0 0.9 24 0.1 44 69 648 0.52 98 8.4 5.4 5.5 42 2.732 79 673 0.52 100 3.1 7.3 6.8 45 0.8 34 86 Reaction conditions: 101.3kPa, WHSV = 0.52 h⁻¹, 7.1 kPa ethanol balanced with H₂.

Example 5. Cu—Zn—La/Beta Catalyst for Ethanol Conversion to Olefins

The DeAl-Beta support was prepared using the same procedure asExample 1. The metal loading procedure for Cu—Zn—La/Beta was alsosimilar to Example 1 except for the use of zinc nitrate hexahydrate andlanthanum nitrate hexahydrate in place of cerium nitrate hexahydrate.The nominal Cu, Zn and La loadings were 1 wt %, 2 wt % and 7 wt %,respectively. The catalyst was tested in the same reactor setup andunder same conditions as Cu—Ce/Beta catalysts in Example 1.

Catalytic Performance

This Cu—Zn—La/Beta catalyst was tested at temperatures of 573 K to 673K. As the temperature increased, ethanol conversion increased from 82%to 99%. Acetaldehyde selectivity dropped significantly from 18% to 4.9%.Both ethylene and propene selectivities were much lower than 10%.Maximum butene selectivity and C₅₊ olefin selectivity were 38% and 49%,respectively. C₃₊ selectivity reached a maximum (88%) at 673 K. Theresults are shown in Table 5 below.

TABLE 5 Ethanol conversion and product selectivities over Cu—Zn—La/Betacatalyst at different reaction temperatures Temp. WHSV Selectivity (K)(h⁻¹) Conv. Acetaldehyde C₂ ⁼ C₃ ⁼ C₄ ⁼ Butadiene C₅₊ ⁼ C₃₊ ⁼ 573 0.5282 18 1.7 0.8 23 0.1 47 71 623 0.52 96 11 6.1 1.4 33 0.1 44 79 673 0.5299 4.9 4.2 1.8 38 0.0 49 88 Reaction conditions: 101.3 kPa, WHSV = 0.52h⁻¹, 7.1 kPa ethanol balanced with H₂. Example 6. Cu-La/Beta Catalystfor Ethanol Conversion to 1,3-Butadiene

The DeAl-Beta support was prepared using the same procedure asExample 1. The metal loading procedure for Cu—La/Beta was also similarto Example 1 except for the use of lanthanum nitrate hexahydrate inplace of cerium nitrate hexahydrate. The nominal Cu and La loadings were1 wt % and 7 wt %, respectively. The catalyst was tested in the samereactor setup and under similar reaction conditions as Cu—Ce/Betacatalysts in Example 1 except using inert helium instead of hydrogenduring the reaction.

Catalytic Performance

This Cu—La/Beta catalyst was tested at 623 K under inert environment.Instead of C₃₊ olefins as the major product, 1,3-butadiene was producedin significantly amount (approaching 40% selectivity). The results aregraphically presented in FIG. 4 .

Example 7. Cu—Zn—La-Beta Catalyst for ABE (Acetone, 1-Butanol andEthanol) Conversion to Olefins

H-Beta Dealumination

H-BEA (SAR=11.5) was obtained by calcinating NH₄-Beta (CP814E, Zeolyst)under 823 K under 1.7 cm³ g⁻¹cat s⁻¹ air for 12 h. 10 g H-Beta was mixedwith 250 mL nitric acid (69% to 70%) in a sealed container at 353 K with500 rpm stirring for 16 h. The solid was centrifuged and washed with DIwater until pH is close to 9. The washed powder was dried under 353 K inoven overnight to remove the remaining water and acid. The sample waslabeled as DeAl-Beta as the support for metal loading.

Loading of Cu, Zn and La

DeAl-Beta was mixed with copper nitrate trihydrate, lanthanum nitratehexahydrate, and zinc hexahydrate in the mortar and ground for 20 min.The mixed powder was homogeneous light green with no blue dots. Themixture was calcinated to 823 K with 1 K/min ramping rate and held for 6h under 13.3 cm³ g⁻¹cat s⁻¹ air to allow a complete decomposition ofmetal precursors and homogeneous distribution of metal species. Thecatalyst has nominal loadings of 1 wt % Cu, 2 wt % Zn and 7 wt % La.

Catalytic Performance Test

The reaction was carried out in a tubular quartz reactor with afixed-bed configuration in a vertical tubular furnace. Typically, 0.3 gcatalyst was treated in situ by heating at 5 K min⁻¹ to 673 K and for 1h under 1.2 cm³ g⁻¹cat s⁻¹ He to remove adsorbed species. After coolingdown to 623 K, the catalyst was reduced under 1. cm³ g⁻¹cat s⁻¹ pure H₂for 30 min. Flow rates of He and H₂ were controlled using mass flowcontrollers. ABE mixture (30 wt % acetone, 60 wt % butanol and 10 wt %ethanol) was delivered by syringe pumps and was evaporated inside the ⅛inches stainless steel transfer lines. The types and concentrations ofthe reactants and products in the stream were measured by agas-chromatograph with thermal conductivity detector (TCD) and a flameionization detector (FID). A gas chromatograph mass-spectrometer (GC-MS)was used to determine the peak position of reactants and products.

Catalytic Performance

Total carbon conversion of ABE mixture was 99.8%. Theoreticalselectivities from ABE are 8.3% ethylene, 29.7% propene and 62.0%butenes, respectively, assuming ethanol was converted to ethylene,acetone was upgraded to propene, and 1-butanol was transformed tobutenes. In the experiment, a significant decrease of all three olefins,particularly ethylene, in comparison with the theoretical selectivitieswas observed. At the same time, larger olefins from pentene to C₈₊olefins were observed due to potential condensation among acetone,1-butanol and ethanol. The results are graphically presented in FIG. 5 .

Example 8. Cu/Silica+Zn-La/Beta Catalyst for Ethanol/1-ButanolConversion to Olefins

H-Beta Dealumination

H-BEA (SAR=11.5) was obtained by calcinating NH₄-Beta (CP814E, Zeolyst)under 823 K under 1.7 cm³ g⁻¹cat s⁻¹ air for 12 h. 10 g H-Beta was mixedwith 250 mL nitric acid (69% to 70%) in a sealed container at 353 K with500 rpm stirring for 16 h. The solid was centrifuged and washed with DIwater until pH is close to 9. The washed powder was dried under 353 K inan oven overnight to remove the remaining water and acid. The sample waslabeled as DeAl-Beta as the support for metal loading.

Loading of Cu and La

DeAl-Beta was mixed with lanthanum nitrate hexahydrate and zinc nitratehexahydrate in the mortar and ground for 20 min. The mixture wascalcinated to 823 K with 1 K/min ramping rate and held for 6 h under13.3 cm³ g⁻¹cat s⁻¹ air to allow a complete decomposition of metalprecursors and homogeneous distribution of metal species. Cu/silica wassynthesized using the same method (copper nitrate trihydrate as Cusource) on commercially available silica (Sigma-Aldrich, pore size 1.5nm, pore volume 1.15 cm³ g⁻¹). Cu/silica contains 1 wt % Cu and La-Betahas 7 wt % La and 2 wt % Zn.

Catalytic Performance Test

The reaction was carried out in a tubular quartz reactor with afixed-bed configuration in a vertical tubular furnace. Typically, 0.3 gcatalyst (physical mixture with Cu/silica to Zn—La/Beta weight ratio of1:1) was treated in situ by heating at 5 K min⁻¹ to 673 K and for 1 hunder 1.2 cm³ g⁻¹cat s⁻¹ He to remove adsorbed species before the test.After cooling down to 623 K, the catalyst was reduced under 1.2 cm³g⁻¹cat s⁻¹ pure H₂ for 30 min. Flow rates of He and H₂ were set usingmass flow controllers. 1-Butanol and butanol-ethanol mixture (61.7 wt %butanol and 38.3 wt % ethanol) were delivered by syringe pumps and wereevaporated inside the ⅛ inches stainless steel transfer lines. The typesand concentration of reactants and products in the stream were measuredby a gas-chromatograph with thermal conductivity detector (TCD) and aflame ionization detector (FID). A gas chromatograph mass-spectrometer(GC-MS) was used to determine the peak position of reactants andproducts.

Catalytic Performance

When only feeding 1-butanol, the primary product was butenes from thedehydration reaction along with minor C₇ and C₈ olefins. Theoreticalselectivities from 1-butanol and ethanol are 33% ethylene and 67%butenes, respectively, assuming ethanol is converted to ethylene and1-butanol is transformed to butenes. In the experiment, a significantdecrease of both olefins, particularly ethylene, in comparison with thetheoretical selectivities was observed. Instead, larger olefins fromhexene to C₈₊ olefins were observed due to potential condensation ofethanol and 1-butanol. The results are graphically presented in FIG. 6 .

While there have been shown and described what are at present consideredthe preferred embodiments of the invention, those skilled in the art maymake various changes and modifications which remain within the scope ofthe invention defined by the appended claims.

1.-16. (canceled)
 17. A method for converting an alcohol to an olefinfraction comprising 1,3-butadiene, the method comprising contacting thealcohol with a catalyst to result in direct conversion of said alcoholto said olefin fraction comprising 1,3-butadiene; wherein said catalystcomprises the following components: (a) support particles comprisingsilicon (Si) and oxygen (O); (b) at least one of copper and silverresiding on and/or incorporated into said support particles; and (c) atleast one lanthanide element residing on and/or incorporated into saidsupport particles.
 18. The method of claim 17, wherein paraffins areoptionally produced along with the olefin fraction in an amount of nomore than 3 vol %.
 19. The method of claim 17, wherein aromatics areoptionally produced along with the olefin fraction in an amount of nomore than 2 vol %.
 20. The method of claim 17, wherein butenes areproduced in an amount of less than 50 vol % in said olefin fraction. 21.The method of claim 17, wherein olefins containing at least five carbonatoms are present in said olefin fraction in an amount of less than 50vol %.
 22. The method of claim 17, wherein said alcohol has one to fourcarbon atoms.
 23. The method of claim 17, wherein said alcohol comprisesethanol.
 24. The method of claim 17, wherein said alcohol is in aqueoussolution in a concentration of no more than 50 vol %.
 25. The method ofclaim 17, wherein said alcohol is a component of a fermentation streamwhen contacted with said catalyst.
 26. The method of claim 17, whereinsaid alcohol is a component of an acetone-butanol-ethanol (ABE)fermentation stream when contacted with said catalyst. 27.-28.(canceled)
 29. The method of claim 17, wherein said lanthanide elementcomprises lanthanum.
 30. The method of claim 17, wherein the1,3-butadiene is produced in a selectivity of at least 35%.
 31. Themethod of claim 17, wherein ethylene is produced in an amount of lessthan vol % in said olefin fraction.
 32. The method of claim 17, whereinpropene is produced in an amount of less than 50 vol % in said olefinfraction.